rest_client: Remove extra check

Since "size_t" is an unsigned integer type, the RHS multiplication
result cannot be negative unless an overflow occurs when assigning to
LHS.  So we change the type of "len" to unsigned as well, to prevent
this corner-case.

modules/rest_client/rest_cb.c

@@ -37,7 +37,7 @@
  */
 size_t write_func(char *ptr, size_t size, size_t nmemb, void *body)
 {
-	int len = size * nmemb;
+	unsigned int len = size * nmemb;
 	str *buff = (str *)body;
 
 #ifdef EXTRA_DEBUG
@@ -47,9 +47,6 @@ size_t write_func(char *ptr, size_t size, size_t nmemb, void *body)
 	if (len == 0)
 		return 0;
 
-	if (len < 0)
-		len = strlen(ptr);
-
 	buff->s = pkg_realloc(buff->s, buff->len + len + 1);
 	if (!buff->s) {
 		buff->len = 0;